:root {
    --background: #f5f7f4;
    --surface: #ffffff;
    --surface-muted: #eaf0ea;
    --text: #17231d;
    --text-muted: #59665f;
    --line: #dce4dd;
    --accent: #2f7251;
    --accent-dark: #21563c;
    --accent-soft: #dcecdf;
    --shadow: 0 20px 60px rgba(27, 62, 43, 0.1);
    color-scheme: light;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--background);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.7;
}

a {
    color: inherit;
}

.site-header,
.site-footer,
main {
    width: min(1180px, calc(100% - 40px));
    margin-inline: auto;
}

.site-header {
    min-height: 92px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 14px;
    text-decoration: none;
}

.brand img {
    border-radius: 13px;
    box-shadow: 0 7px 20px rgba(23, 35, 29, 0.13);
}

.brand span {
    display: grid;
    line-height: 1.2;
}

.brand strong {
    font-size: 18px;
}

.brand small {
    margin-top: 4px;
    color: var(--text-muted);
    font-size: 12px;
    letter-spacing: 0.08em;
}

.site-nav,
.site-footer nav {
    display: flex;
    flex-wrap: wrap;
    gap: 22px;
}

.site-nav a,
.site-footer a {
    color: var(--text-muted);
    font-size: 14px;
    text-decoration: none;
}

.site-nav a:hover,
.site-footer a:hover,
.site-nav a:focus-visible,
.site-footer a:focus-visible {
    color: var(--accent-dark);
    text-decoration: underline;
    text-underline-offset: 4px;
}

.hero {
    min-height: 660px;
    display: grid;
    grid-template-columns: minmax(0, 0.92fr) minmax(420px, 1.08fr);
    align-items: center;
    gap: 80px;
    padding: 72px 0 96px;
}

.eyebrow {
    margin: 0 0 12px;
    color: var(--accent);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1 {
    max-width: 620px;
    margin-bottom: 22px;
    font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
    font-size: clamp(40px, 5vw, 66px);
    line-height: 1.16;
    letter-spacing: -0.035em;
}

h2 {
    margin-bottom: 14px;
    font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
    font-size: clamp(30px, 3.8vw, 44px);
    line-height: 1.25;
}

h3 {
    margin-bottom: 10px;
    font-size: 21px;
    line-height: 1.35;
}

.hero-lead,
.section-heading > p:last-child,
.language-section > div > p:last-child {
    max-width: 720px;
    color: var(--text-muted);
    font-size: 17px;
}

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin: 32px 0;
}

.button {
    display: inline-flex;
    min-height: 48px;
    align-items: center;
    justify-content: center;
    padding: 11px 20px;
    border: 1px solid var(--accent);
    border-radius: 999px;
    font-weight: 650;
    text-decoration: none;
}

.button-primary {
    background: var(--accent);
    color: white;
}

.button-primary:hover,
.button-primary:focus-visible {
    background: var(--accent-dark);
}

.button-secondary {
    background: transparent;
    color: var(--accent-dark);
}

.button-secondary:hover,
.button-secondary:focus-visible {
    background: var(--accent-soft);
}

.feature-list {
    display: grid;
    gap: 9px;
    margin: 0;
    padding: 0;
    color: var(--text-muted);
    list-style: none;
}

.feature-list li {
    position: relative;
    padding-left: 25px;
}

.feature-list li::before {
    position: absolute;
    left: 0;
    color: var(--accent);
    content: "✓";
    font-weight: 800;
}

.phone-screenshots {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
    padding: 38px 28px;
    border: 1px solid rgba(47, 114, 81, 0.14);
    border-radius: 40px;
    background: linear-gradient(145deg, rgba(255, 255, 255, 0.92), rgba(220, 236, 223, 0.72));
    box-shadow: var(--shadow);
    overflow: hidden;
}

.phone-screenshots img {
    width: min(29%, 200px);
    height: auto;
    border-radius: 20px;
    box-shadow: 0 13px 38px rgba(25, 45, 35, 0.18);
}

.phone-screenshots .featured-shot {
    width: min(34%, 220px);
    transform: translateY(-12px);
}

.content-section {
    padding: 88px 0 104px;
    border-top: 1px solid var(--line);
}

.section-heading {
    margin-bottom: 38px;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.topic-card {
    min-height: 280px;
    display: flex;
    flex-direction: column;
    padding: 30px;
    border: 1px solid var(--line);
    border-radius: 24px;
    background: var(--surface);
    text-decoration: none;
    transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.topic-card:hover,
.topic-card:focus-visible {
    border-color: var(--accent);
    box-shadow: 0 16px 38px rgba(27, 62, 43, 0.08);
    transform: translateY(-3px);
}

.card-index {
    margin-bottom: 34px;
    color: var(--accent);
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 13px;
}

.topic-card p {
    color: var(--text-muted);
    font-size: 15px;
}

.card-link {
    margin-top: auto;
    color: var(--accent-dark);
    font-size: 14px;
    font-weight: 700;
}

.language-section {
    display: grid;
    grid-template-columns: minmax(260px, 0.75fr) minmax(0, 1.25fr);
    gap: 70px;
    align-items: start;
    margin-bottom: 104px;
    padding: 48px;
    border-radius: 28px;
    background: var(--surface-muted);
}

.language-links {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
}

.language-links a {
    padding: 11px 14px;
    border: 1px solid transparent;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.75);
    color: var(--accent-dark);
    font-size: 14px;
    text-decoration: none;
}

.language-links a:hover,
.language-links a:focus-visible {
    border-color: var(--accent);
    background: white;
}

.site-footer {
    padding: 42px 0;
    border-top: 1px solid var(--line);
}

.footer-primary,
.footer-legal {
    display: flex;
    justify-content: space-between;
    gap: 28px;
}

.footer-primary p {
    margin: 6px 0 0;
    color: var(--text-muted);
    font-size: 14px;
}

.footer-legal {
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
    color: var(--text-muted);
    font-size: 12px;
}

.record-links {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

.policy-main {
    width: min(820px, calc(100% - 40px));
    margin: 54px auto 96px;
}

.policy-article {
    padding: clamp(28px, 6vw, 64px);
    border: 1px solid var(--line);
    border-radius: 28px;
    background: var(--surface);
    box-shadow: 0 18px 50px rgba(27, 62, 43, 0.07);
}

.policy-article h1 {
    margin-bottom: 12px;
    font-size: clamp(36px, 6vw, 54px);
}

.policy-article h2 {
    margin-top: 42px;
    font-family: inherit;
    font-size: 23px;
}

.policy-article p,
.policy-article li {
    color: #38463f;
}

.policy-article a {
    color: var(--accent-dark);
}

.policy-meta {
    margin-bottom: 38px;
    color: var(--text-muted);
    font-size: 14px;
}

.policy-note {
    margin: 28px 0;
    padding: 18px 20px;
    border-left: 4px solid var(--accent);
    background: var(--surface-muted);
}

@media (max-width: 940px) {
    .hero {
        min-height: auto;
        grid-template-columns: 1fr;
        gap: 52px;
        padding-top: 46px;
    }

    .hero-copy {
        max-width: 760px;
    }

    .card-grid {
        grid-template-columns: 1fr;
    }

    .topic-card {
        min-height: 230px;
    }

    .language-section {
        grid-template-columns: 1fr;
        gap: 24px;
    }
}

@media (max-width: 680px) {
    .site-header,
    .site-footer,
    main {
        width: min(100% - 28px, 1180px);
    }

    .site-header {
        align-items: flex-start;
        flex-direction: column;
        padding: 18px 0 20px;
    }

    .site-nav {
        width: 100%;
        gap: 12px 20px;
    }

    .hero {
        padding: 38px 0 72px;
    }

    h1 {
        font-size: 39px;
    }

    .phone-screenshots {
        gap: 10px;
        padding: 24px 14px;
        border-radius: 28px;
    }

    .phone-screenshots img {
        border-radius: 12px;
    }

    .content-section {
        padding: 70px 0 78px;
    }

    .language-section {
        margin-bottom: 76px;
        padding: 30px 22px;
    }

    .language-links {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .footer-primary,
    .footer-legal {
        align-items: flex-start;
        flex-direction: column;
    }

    .site-footer nav {
        gap: 12px 18px;
    }

    .policy-main {
        width: min(100% - 28px, 820px);
        margin-top: 30px;
    }

    .policy-article {
        border-radius: 22px;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition-duration: 0.01ms !important;
    }
}